Telephone-exchange system.



F. A. LUNDQUIST.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED MAR. s. 1917.

1,252,464. Patented Jan. 8,1918.

//7 ven/or: Ev /7A A. Z u/vdqulls'f' M KA'LX/ UNITED STATES PATENT o FIo FRANK, a; LUNDQUIST, or cnrcaeo, ILLINOIS, 'Assnmon 'ro wnsrnnln ELECTRIC conrm, moonronnrnn, or new YORK, mm, A conronn'rron or new YORK.

TELEPHONE-EXCHANGE srsrnn.

Specification of Letters Patent.

Patented Jan. s, 1918.

. Application filed men s, 1917. Serial in. 152,238.

To all whom it may concern:

Be it known that I, FRANK A. Lonnqmsr a citizen of the United States, residing at Chicago, inthe county of Cook and State of Illinois, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone ex change systems, and more particularly to automatic switches-of the type employed in such systems.

The object of the invention is to provide a new and improved selector switch which shall be'rapid in operation and which may be controlled in three selective movements by any standard substation impulse sending device.

In accordance with' this invention, called line terminals are arranged in flat panels of the well-known type, and a set of brushes is rovided to cooperate with each panel. The

rush sets in each switch are spirally arranged on a shaft so that brush selection may be accomplished by rotation of the shaft. A stop shaft, arranged for longitudinal and rotary movements, and provided wlth a set of spirally arranged lugs, is elevated 1n the second selective movement of the switch and is rotated in the. third movement so as to bring one of the lugs into position to be engaged by a stop arm carried on the brush shaft. The brush shaft is released and allowed to fall under the control of a governor during the rotation of the stop shaft, so that, at the end of such rotation, the selected brushes will have been moved close to the selected terminals, and will come to rest on.

contact bank shown at 4, The brushes 3- are fixed to and arranged spirally about a shaft 5, being spaced apart a distance e ual to the distance from the top of one panel to the top of the next panel. A gear wheel 6 is carried by a bushm 7 at the lower. end of the shaft 5, the bus ing 7 being splined to the shaft so as to. rotate therewith but to be unaffected by longitudinal motion thereof. An auxiliary shaft 8, rotatably mounted in any convenient at its upper end, will mesh with the gear wheel 6. A spiral spring 10, one end of which'is held by a pin -11, tends to rotate the shaft 8 in a counter-clockwise direction, but the shaft is normally held against rotation by the engagement of a pawl 12 with lugs 13 carried on the gear wheel 6. The pawl 12 has two arms and is pivoted at 14 so that, when operated, it will allow the escapement of the shaft 8, and the consequent rotation of brush shaft 5. The lugs 13 are placed alternately on the upper and lower faces of the wheel 6, the distance between lugs corresponding to the angle between successive brushes 3 so manner, is positioned so that a p1n1on 9, fixed rigidly that each step of the pawl 12 will successively bring the sets of brushes into operative relation with the terminal banks 4.

A stepping magnet SM is provided with an armature 15 for actuating the switch. The armature 15 is pivotally mounted at 16 and has pivoted to its up or end a lever 17. A hook 18 at the end of lever 17 enga es the pawl 12 so long as the rod 19 holds lever 17 in normal position, but is idle after the rod 19 has been depressed one step. The rod 19 has at its lower end a rack 20 which meshes with teeth 21 of a pinion 22. The

pinion 22 has in addition a set of ratchet taryfs'tep of the A sleeve 28 is rotatably mounted on the auxiliary shaft 8 and is provided at its up: per end witha rotary ratchet 29 and a vertical ratchet 30. A pin 31, fixed in the shaft 8, normally. supports sleeve 28, while a spring 32-holds it in its normal rotary position. A series of lugs 33 project from the shaft 28 at equal intervals and are spirally arranged so that rotary steps of the sha will bring the lugs successively into the path of the stop arm 34. A pawl 35, carried by a lever 36,'is arranged to rotate the ratchet 29, while a pawl 37, carried by the armature 15, co6perates with the ratchet to elevate sleeve 28.

29 and 30 by cams 40 and 41, carried by the bushing 7, but will engage and hold their respective ratchets after the first. ro-

brush shaft 5. A lug 42, carried by the-rod 19, holds the pawl 37 inoperative while the rod 19 is in normal position, but allows it to operate after the first downward step of said rod. After the second downward step of the rod 19 a lug 43 holds pawl '37 inoperative. In this position of the rod 19 the end 77 of a lever 46 will be engaged between pins 47 of the lever 17.

i the rod 19 been set in its path.

The operation of the stepping magnet closes springs 48 intermittently and in position-2 of therod 19 causes of the stop support 28. In position 3 of the operation of the stepping magnet imparts a to-and-fro motion to the lever 46. The first attraction of the armature 15 at this time causes a catch 49 to become disengaged from an arm 50. Such motion of the lever 46 also actuates the pawl 35 to step the ratchet 29., The arm 50 may be the projecting end of a driving ribbon 51, which is secured to a bushing 52. The bushing 52 is rotatably mounted at the lower end of brush-shaft 5, but is held against vertical movement on said shaft in anyconven-.

ient manner. Upon the removal of the catch 49 from the arm 50 the shaft 5 falls, its velocity being controlled by a governor indicated at 53, until the stop arm 34 comes into engagement with the lug 33, which has The governor 53 may be of any desired type, being preferably arranged-to control the downward movement of ribbon 51, but to be held inoperative during upward movement of said ribbon.-

During brush selection a pinion 54, rigidly mounted at the bottom of the shaft 8, will be rotated, so as to move the rack 55 with which it meshes. The restoring mag-- net RM has an armature lever 56 pivoted at 57. A lever 58 is pressed by aspring 59 lever 60 which is pivoted to the against a armature 56. 'The movement of levers 58 and 60 is restricted by a pin 61 on rack 55.

The pawls 38 and 39 are normally held out of engagement with ratchets the elevation.

' cientlyto allow lever 60 to engage in its recess 64 the. end of arm 62 when the restoring magnet RM becomes energized. Such a motion of the lever 60 allows the switch 78 controlled by lever 58 to advance to position 3. A bell-crank lever 67 is pivoted at the upper end of armature 56 and is held in normal position by a in 68 fixed to the ribbon 51. When in t is ositi'on lever 67 holds open the contact springs 69.

Upon the downward movement of ribbon 51,

pin 68 allows the lever 67 todrop into engagement with a lug 71 carried by a roller arm 72. When the magnet RM is energized, a lug 73 on lever 67 will engage the lug 71 and force the roller arm 72 to the left, causing the roller 74 to press the ribbon 51 against the constantly rotating power driven wheel 75. When the-ribbon 51 reaches normal position, the engagement of the pin 68 with lever 67 causes the opening of contact springs 69, and the consequent deenergization of the release magnet and the return of roller 74 to its idle position. The deenergization of the release magnet also causes the lever 60 to raise arm.62, which I presses its roller 63 against rack 55. The rack 55, being pressed against power wheel 75, is moved to the right until it reaches normal position, at which time the pin '61 draws lever 60 out of engagement with arm 62 and allows roller 63 to return to idle position. This movement of lever 60 also returns switch 78 to normal.

The operation of the switch is as follows: When a selector switch seizes a trunk leading to the connector switch it closes a circuit.

from grounded battery, through the winding of the stepping relay SR, conductor 2, through the selector and line switches, through the substation apparatus,'over the conductor 1 to ground. The consequent energization of relay SR closes a circuit from grounded battery, armature and front contact of relay SR, through the winding of slow-release relay 74 to ground. The subscriber now operates his dial to send a series of impulses which interrupt the circuit of the relay SR causing it tovibrate its armature. Each time that the relay SR retracts its armature it completes. a circuit from grounded battery, armature and back contact of relay SR, through the winding of the stepplng magnet SM, contact springs 45,

front contact and armature of relay 74 to ground. The intermittent energization of the magnet SM operates the pawl 12 to allow rotation of the brush shaft until the desired brush set is in operative relation with the.

mains energized throughout each series of impulses. At the end of the first series of impulses it denergizes and steps the pinion 22 one step, thus lowering the rod 19 into position 2. The subscriber now sends another series of impulses, operating the magnet SM as before. Since the pawl 37 is now in operative relation to the ratchet 30, the stop shaft 28 will be elevated one step upon each attraction of the armature 15. At the termination of this series of impulses the magnet 26 again denergizes and the rod 19 is moved into position 3. The subscriber now sends the final series of impulses, causing as before, the operation of the stepping magnet. Upon the first attraction of the armature 15 the catch 49 is removed from the arm 50 and the brush shaft 5 starts to fall under the control of governor 33. The continued operation of the armature 15 causes the rotation, in the manner previously described, of the stop shaft 28 until the desired lug 33 is placed in the path of stop arm 3%.

- At completion of this series of impulses the deenergization of magnet 26 steps the rod 19 into position 4, at which time a lug 44, carried by said rod, holdsopen the contact springs 45 so that an accidental operation of the stepping relay would not change the position of the switch. The shaft- 5, which was falling during the setting of the lugs 33, is arrested by the lug which has been placed in the path of arm 34.- with its brush 3 in engagement with a desired line terminal, almost immediatel after the completion of the final series 0 impulses. Testing and ringing of the wanted line if idle now take place through contacts ofthe side switch 79 in any well-known manner, and the connection between the calling and called line is then complete.

At the close of the conversation the subscriber breaks at his switchhook the circuit for the stepping relay SR, which retract-s its armature, breaking the circuit of relay 74, which thereupon denergizes. In retracting its armature, relay 7 4 closes a circuit for the release magnet RM from ground, armature and back contact of relay 74, contact springs 69, through the winding of the magnet RM and contact springs 66 to battery -and ground.

The armature 56 of the magnet RM being attracted causes the vertical restoration of the brush shaft in the manner previously described. The armature 56, when attracted, also brought a rod 76 into engagement with ground. In attracting armature 56, the

pawls 24 and 25, removing them from engagement with the teeth 23 so .that pinion 22 is restored and moves the rod 19 back to its normal position. When the pin 68 engages, in its upward travel, lever 67 springs- 69 are opened and the circuit for the release 70 magnet is broken. The lever 60 now causes the return of the rack 55 to normal in the manner previously described, and the rack 55 during restoration rotates shaft- 8, winding up the spring 10 and turning gear wheel 6 back to normal. The pawl 12 is arranged so as not to obstruct the lugs 13 when the gear wheel 6 is moving in a counter-clockwise direction. When the rack 55 reaches normal the pin 61 restores levers 60 and 58, in the manner described, and the switch is now in readiness for the next call.

Should the subscriber abandon the call before the release and downward movement. of the ribbon 51, a circuit for the release magnet would be completed from grounded battery, contact springs 66, winding of magnet RM, switch 78 in its second position, back contact and armature of relay 741 to so I magnet RM would break its own circuit,

-since switch 78 advances to its third position during the attraction of armature 56. The rack 55, rod 8 and brush shaft 5 would, therefore, be restored as before. A

What 1s claimed is: i 1. In an automatic switch, a plurality of contacts, a plurality of brushes to cotiperate with said contacts, a movable shaft to carry said brushes, means for selecting a setof brushes, a rotatable rod, a plurality of stop members on said rod, means for initiating the travel of said brushes over said contacts, and means actuated duringsaid travel for rotating said rod to position a selected stop member to arrest said brushes on a selected contact.

2. In an automatic switch, a plurality of terminals, a plurality of brushes arranged to travel over and make-contact with said 110 terminals, a stop arm associated with said brushes, a catch to normally prevent the travel of said brushes over said contacts, a movable rod, a pluralit of stop members on said rod, means for se ecting a brush to be associated with said terminals, means for releasing said catch, and means operable subsequent to the release of said catch for positioning a selected stop member in the path of said stop arm, all of said means being responsive to directive impulses.

3. In an automatic switch, a plurality of stationary contacts arranged in main groups and sub-groups, a movable shaft, a plurality of brush sets mounted thereon, means to operate said shaft to render one of said brush sets operative with relation to the main group of contacts served by it, a. control Edi mechanism, a stop member carried thereby,

means to position 'saiei control mechanism in response to a .plurahty of selective ,operations, means toadvance a selected brush into 5 engagement with a desired terminal in a d sired sub-group in accordance with the setting of said control mechanism, and means ting said control mechanism.-

to advance said selected hrlish toward a desired position during the operation of set- 10 In witness whereof, I hereunto subscribe my name this 28th day of Feb., A. D. 1917.

FRANK A. LUNDQUIST. 

